There is two systems.

When we replaced the system to new one, I wrote the attached report.

New signal transfer system has low latency for monitoring the transmitted light of 300 meter FP cavity.

Today I found two receiver modules in the center-room.

Both of old and new system modules are placed behind a LCD monitor for digital control system of optical lever.

Maybe signal sender modules can be found at both end rooms.

Because optical cables are unplugged for new system, please check the cable assignments

by sending some signal from the end-room.